A tire and wheel assembly comprises a wheel rim, a tire and an inner tube having a valve stem, an opening in the wheel rim for receiving the valve stem, a flap disposed between the wheel rim and the inner tube, and a reusable shield interposed between the flap and the wheel rim in proximity to the rim opening to prevent exposure of the flap through the rim opening. The shield includes a relatively small opening for snugly receiving the valve stem, has a size sufficient to completely cover the rim opening, and is constructed of a resilient material which is resistant to deterioration when exposed to substances such as grease, oil, and road salts.